Project Summary (Research Project 4) Proteinuria is an early and sensitive marker of kidney damage and a risk factor for chronic kidney disease (CKD) progression, cardiovascular disease and all-cause mortality. Several cross-sectional epidemiological studies have reported an association between sodium intake and albuminuria (majority of proteinuria) that is independent of blood pressure (BP). In addition, a handful of small clinical trials have suggested a reduction in dietary sodium intake may decrease albuminuria in patients with CKD. The overall goal of this randomized controlled trial is to study the effect of dietary sodium reduction on albuminuria in CKD patients with albuminuria. A total of 150 participants with CKD and albuminuria will be recruited from 3 medical centers in the New Orleans area. They will be randomly assigned to either a 16-week intensive behavioral modification program designed to reduce dietary sodium intake to 2,400 mg/day or to usual care in a 1:1 randomization ratio. The primary outcome will be the difference between the active intervention and control groups for change in urinary albumin-to-creatinine ratio from baseline to 16 weeks of follow-up. Urinary albumin-to-creatinine ratio will be assessed as the average of two 24-hour urine collections at each time point. Secondary outcomes will include estimated glomerular filtration rate (eGFR), BP, and number of antihypertensive medications. Urinary sodium excretion will be used to measure the success of the intervention. Racial differences in albuminuria changes due to reduction in dietary sodium intake will be analyzed. Urinary angiotensinogen excretion, a biomarker of intrarenal renin-angiotensin system activity and sodium-sensitivity will also be evaluated in relation to changes in albuminuria during the dietary sodium reduction intervention. The intervention program will be modeled on best practices derived from the investigators prior experience in conducting sodium reduction behavioral interventions. The intervention program will address individual barriers to long-term sodium reduction and generate collective enthusiasm and motivation for adherence to the program. Study staff will receive training and direct support from a consultant with extensive experience in successful implementation of behavioral and dietary modification interventions. Results from this study will clarify the role of dietary sodium reduction in management of CKD patients with albuminuria and its potential to halt the progression of CKD, a global public health concern. The study will explore the interaction of race/ethnicity and urinary angiotensinogen excretion with dietary sodium reduction on albuminuria in CKD patients. This COBRE research project will provide the junior faculty investigator protected time, the opportunity to lead a multidisciplinary research team, and facilitate her authorship of high quality peer reviewed publications which will enhance her career development and allow for a successful transition to become a competitive independently funded physician-scientist.